Wireless communication is an increasingly popular means of personal communication in the modern world. People are using wireless networks for the exchange of voice and data as an alternative to using a wire infrastructure. In principle, a user can seek information over the Internet or call anyone over the public switched telephone network (PSTN) from any place inside the coverage area of the wireless network.
In a typical cellular wireless system, an area is divided geographically into a number of cell sites, each defined by a radio frequency (RF) radiation pattern from a respective base transceiver station (BTS) antenna. The BTS antenna in the cells are in turn coupled to a base station controller (BSC), which is coupled to a telecommunications switch (e.g., mobile switching center (MSC)) or gateway (e.g., packet data serving node (PSDN)) that provides connectivity with a transport network such as the PSTN or the Internet.
When a mobile station (MS) (such as a cellular telephone, pager, or appropriately equipped computer, for instance) is positioned in a cell, the MS and BTS can communicate with each other in various channels over an RF air interface. Communications from the BTS to an MS are considered to be in a “forward” direction, so the air interface channels used to carry such communications are referred to as the “forward link” channels. Conversely, communications from an MS to the BTS are considered to be in a “reverse” direction, so the air interface channels used to carry such communications are referred to as “reverse link” channels.
Traditionally, in-building communication, such as within a home or office building has been conducted via landline communication technology. Now, wireless communication is increasingly being used within buildings, replacing the more traditional landline communication facilities. Use of a MS instead of a fixed landline terminal can conveniently allow for free movement within buildings as well as into and out of the buildings. Traditional wire infrastructure private branch exchange (PBX) may be replaced, for example, by a wireless PBX to route phone calls and Internet connections inside a building.
A wireless communications technique commonly used to allow multiple users on the same channel is code division multiple access (CDMA). CDMA permits multiple users to use the same wireless communication channel at the same time, which allows the network infrastructure to support more wireless users. In CDMA, a narrowband data signal from a MS is spread over a spectrum of frequencies in order to create a broadband signal for transmission to a BTS. When the BTS receives the broadband signal, it uses a unique code to recover the transmitted narrowband data signal from the multiple of signals encountered by the BTS.
Distributed antenna systems (DAS) have been developed in order to provide better in-building coverage. In a DAS, a number of antenna units are distributed throughout a geographic area and controlled by a DAS controller. Antenna units are configured to communicate with mobile stations located within their respective coverage areas. In wireless DAS (WDAS), remote antenna units are communicatively coupled with a WDAS controller (or hub) via wireless links. U.S. patent application Ser. No. 10/222,015, filed by Mark L. Yarkosky entitled “Method and system for decreasing noise from wireless repeaters” provides further background and is hereby incorporated by reference.